Nitrogen removal from distillate fuel with sulfur halides



United States Patent Olfice 3,407,136 NITROGEN REMOVAL FROM DISTILLATE FUEL WITH SULFUR'HALIDES Daniel F. Jonusz, Cranbury, and Jack Ryer, East Brunswick, N.J., assignors to Cities Service Oil Company, Bartlesville, kla., a corporation of Delaware No Drawing. Filed Jan. 24, 1966, Ser. No. 522,416

3 Claims. (Cl. 208- 254) ABSTRACT OF THE DISCLOSURE Sulfur halides are used for the removal of nitrogen-containing compounds to improve the characteristics of hydrocarbon distillate fuel. Sulfur mono-, di-, and tetra halides may be employed, for example, sulfur monochloride, sulfur monobromide, sulfur monofluoride, sulfur dichloride, sulfur tetrachloride, etc. The hydrocarbon fuel is intimately contacted with the sulfur halide at a temperature of 0-100 C. to form a precipitate of the nitrogen containing impurity, which is then removed from said fuel.

The present invention relates to a method for improving the characteristics of petroleum products and more particularly to improving the stability of fuel oils.

Hydrocarbon distillate fuels treated in accordance with the present invention include generally fuels having boiling ranges between about 100 F. and 1200" F. and may include gasoline, kerosene, diesel fuels, heating fuels, jet fuels and the like. Such distillates may be obtained from any suitable source, such as by frictionation of crude oils or may be obtained from various hydrocarbon conversion or refining processes commonly used in the treatment of hydrocarbon oils. Such processes include, for instance, catalytic or thermal cracking or reforming, coking, alkylation, polymerization and the like. The process of the present invention is especially applicable to kerosenes and to fuel mixtures containing substantial portions of kerosene. Fuels containing substantial amounts of kerosene include, for instance, jet fuels which frequently contain from 30 to 60 volume percent or more of kerosene and frequently have boiling ranges between about 100 F. and 600 F. The invention is also applicable to fuel compositions containing substantial amounts, such as at least about 30 volume precent, of hydrocarbon distillates of the type described above.

Distillates such as those described above have a strong tendency to form gums and sediments, especially after prolonged periods of storage or exposure to high temperatures. Such gums and sediments are highly undesirable and may clog fuel lines, valves, meters, filters, etc. as well as form deposits in internal combustion engines or fuel burners. The formation of gums and deposits in hydrocarbon distillates are attributable to the presence of a variety of compounds therein. Certain compounds, notably, nitrogen cotnaining compounds and phenolic compounds, such as phenol, cresol, xylenols, etc. are noted for their tendency to form gums and sediments. Accordingly, a method which would selectively remove the abovementioned compounds from a hydrocarbon distillate would enhance the stability of the hydrocarbon distillate.

An object of this invention is to provide a method for improving the characteristics of petroleum products.

It is another object of this invention to provide a method for improving the stability of fuel oils.

It is yet another object of this invention to provide a method for the removal of nitrogen compounds and phenolic compounds so as to improve the stability of fuel oils.

These and other objects of this invention will become 3,407,136 Patented Oct. 22, 1968 apparent from a detailed description of the invention which follows.

It has been found that the addition of a liquid or gaseous sulfur mono-, di-, or tetra halide to a hydrocarbon distillate results in a pronounced decrease in the percent nitrogen present and in the concentration of phenolic compounds present. Illustrative of the sulfur mono-, di-, and tetra halides referred to above are: sulfur monochloride, sulfur monobromide, sulfur monofluoride, sulfur dichloride, sulfur tetrachloride, etc. The reduction in the amount of nitrogeneous and phenolic compounds results in improved stability for the particular hydrocarbon distillate.

The sulfur chlorides, and particularly sulfur monochloride, i.e., S Cl are preferred in the practice of thsi invention. The quantities of sulfur halide employed are quite small. The amount employed will vary with the amount of deleterious material contained in the hydrocarbon distillate. The amount of sulfur halide to be added may range from about 25 parts per million by volume (ppm) to about 1,000 p.p.m., but a range of from about p.p.m. to about 500 p.p.m. is preferred. The hydrocarbon distillate and the sulfur halide are contacted and agitated at a temperature of from about 0 C. to about 100 C., with a temperature range of from about 24 C. to about 30 C. being preferred, i.e., room temperature. The contacting may be carried out over a period of from about 1 hour to about 10 hours, with a contact period of from about 3 hours to about 7 hours being preferred. This is followed by filtering the treated oil through filter paper, or a material such as clay or the like, or by settling.

Subsequent to treatment, the nitrogen content of the hydrocarbon distillate has been essentially eliminated and the phenolic content has been significantly reduced. In addition the treatment with the sulfur halide produces no adverse side effects; in fact, the distillation curves prior to, and subsequent to, treatment are practically identical.

The following specific example will illustrate the application and benefits of the present invention in the treatment of hydrocarbon distillates.

Example To each of three separate 3-liter flasks was added two liters of raw untreated kerosene, containing 0.098% nitrogen, and one milliliter of sulfur monochloride. Each of the flasks were equipped with a reflux condenser, and a stirrer to agitate the contents of the flask during the contact, or treating. The contact period in each instance was six (6) hours; however, each of the samples was contacted at a different temperature for the entire six hour period. The temperatures were: 0 C., room temperature (24 C.30 C.) and 100 C. After six hours the oil was water washed until the washings were neutral. The washed product was dried and filtered. In the case of the contacting which was carried out at 100 C., it was necessary to distill the product because of discoloration. The significant decrease in percent nitrogen and phenolic concentration can be appreciated from Table I below.

Therefore what is claimed is: 1. Method of improving stability of a hydrocarbon distillate fuel by removal of undesirable nitrogen contain- 3 ing impurities therefrom which comprises intimately contacting said fuel with a compound selected from the group consisting of the mono-, diand tetra-halides of sulfur to thereby form a precipitate containing at least a portion of such impurities and removing said precipitate from said fuel.

-2. The method of claim 1 in which between about 25 and about 1000 parts per million of the halide of sulfur is intimately contacted with the hydrocarbon fuel at a temperature of from about 0 C. to about 100 C. for a period of time between about 1 and about 10 hours.

3. The method of claim 2 in which said halide of sulfur is sulfur monochloride.

4 References Cited UNITED STATES PATENTS 413,187 10/1889 Kendall 208241 5 2,114,313 4/1938 Patrick 208241 2,114,314 4/193 8 Patrick 208-241 2,114,315 4/193 8 Patrick 208241 3,291,724 12/1966 Gleim 208241 10 DELBERT E. GANTZ, Primary Examiner.

G. J. CRASANAKIS, Asrista-nt Examiner. 

